Pneumatic and hydraulic jack for garage use



March 18, 1969 NORIMASA SANO 3,433,453

PNEUMATIC AND HYDRAULIC JACK FOR GARAGE USE Filed Jan. 25, 1967 Sheet I012 INVENTOR NORIMQSF) SAND BY j w y ATTORNEY Sheet March 18. 1969NORIMASA SANO PNEUMATIC AND HYDRAULIC JACK FOR GARAGE USE Filed Jan. 25,1967 km m INVENTOR AER/M1959 SAND BY g 72 ATTORNEY United States Patent3,433,458 PNEUMATIC AND HYDRAULIC JACK FOR GARAGE USE Norimasa Sano,Tokyo, Japan, assignor to Yasui Sangyo Company, Ltd., Tokyo, Japan FiledJan. 25, 1967, Ser. No. 611,699 US. Cl. 254-93 7 Claims Int. Cl. B66f3/24 ABSTRACT OF THE DISCLOSURE The present invention relates to jackmechanisms for garage use, particularly, provided with oil hydrauliccylinder and piston arrangements which are driven or operated bycompressed air and hydraulic oil.

Heretofore, a jack of manual oil pump type has been used for liftingheavy weights, particularly, in the automotive field, but it isinconvenient for operation, because a lot of human labor is consumed,and its lifting power for a load is considerably slow in action. While ajack of electric motor pump type is of a complicated and relativelylarge construction, it has a disadvantage that it is expensive. On theother hand, a jack of compressed air operation type is easy and simpleto handle, but its size of construction is pretty big if a relativelylarge area lifted by the action of compressed air is to be desired.Hence it is also inconvenient for handling, and besides, it isimpossible to have a stronger lifting power.

A pneumatic and hydraulic jack of this invention has been invented forthe purpose of overcoming the above defects and disadvantages. In thejack of this invention, compressed air drives or operates an air pistonhaving a small area, which, in turn, drives an oil plunger secured to anend of the air piston, and then, an oil piston having a relatively largearea is driven by an oil pressure generated by the oil plunger so that alarge lifting power will be imparted to the load. Recently a source ofcompressed air is readily available in shops where automobile repairworks are done. In addition, in operation, the jack of this inventioncan be operated easily and simply in an effective manner by an operatinglever accessible to an operator, which is one of the essential featuresof the invention.

Briefly stated, in accordance with a preferred embodiment of theinvention, the pneumatic and hydraulic jack comprises a horizontallydisposed jack cylinder body, an air piston, an oil pressure meansincluding an oil plunger connected to one end of the air piston rod, anelongated rod for controlling an air valve, an elongated rod forcontrolling a needle valve for releasing oil pressure, an operating armfor mounting a load plate, and an operating lever for controlling theair valve and the needle valve, disposed on an elongated tubular memberwhich serves as a steering shaft.

It is therefore an object of the invention to provide an oil hydraulicjack operated by compressed air in which an air piston is driven bycompressed air fed into the cylinder body with a simple operation of theoperating lever, and an oil plunger connected to one end of the ice airpiston rod is driven thereby in order to increase oil pressure in theoil pressure means and impart a lifting power to a load plate.

Another object of the invention is to provide a pneumatic and hydraulicjack for garage use in which a lifting power is increased by driving anoil piston of a relatively large area with an increased oil pressureresulting from driving an air piston of a relatively small area.

Still another object of the invention is to provide an improved jackwhich can work based on both actions of air and oil pressure and whichhas a high lifting power With a compact construction compared to theconventional one.

Still another object of the invention is to provide an improved noveljack in which its operating lever for controlling the valves is mountedon the elongated rod which can be selectively positioned on a mountingplate having a plurality of slots through which the rod can be fixed atas convenient a position as possible for an operator, whereby theoperator can select the position of the operating lever at as convenienta position as desired with no hindrance in his way.

Still an additional object of the invention is to provide a lessexpensive garage jack than the one of electric motor type in which it isautomatically driven by the compressed air readily available inautomobile repair shops, no human labor is consumed, a lifting power forload can be accelerated, its operating hour therefore can be reduced,and its air motor means can be made as compact as possible.

Still an additional object of the invention is to provide an improvedgarage jack in which an operating lever for effecting a remote controlon the lifting speed, stop and drop of load is disposed at as suitable aposition as desired by the operator.

Other objects together with the foregoing are attained in the preferredembodiment of the invention described in the accompanying descriptionand illustrated in the accompanying drawings, in which:

FIG. 1 is a perspective view of the jack of the invention showing itsinterior except its forward portion having a load plate.

FIG. 2 is a side elevation of the jack of the invention showing theforward portion with the load plate, except its steering shaft, with aside frame removed.

FIG. 3 is a top plan view showing the valve operating mechanism takenalong the AA line of FIG. 2.

FIG. 4 is a similar view to FIG. 3 showing the action of the valvemechanisms.

FIG. 5 is a longitudinal sectional view of the air piston and the coilhydraulic means of the jack of the invention.

FIG. 6 is a fragmentary elevational view taken along the BB line of FIG.1.

In proceeding the description of the garage jack of the invention, firstof all, its compressed air motor means is described.

A source of compressed air (not shown) is connected to an air inlet 15(FIG. 1) which is also to an air inlet 17 (FIG. 5) through an air hose16. An air valve 27 urged upwardly by a spring 63 is opened tocompressed air, and the compressed air thus supplied enters an airchamber 29 through a passage 28, and fills the chamber 29 withcompressed air to increase an air pressure in the chamber 29.Accordingly, an air piston 30 is pushed leftward in FIG. 5 owing to anincreased air pressure in the air chamber 29.. The air piston 30 isurged rightward by the action of a coiled compression spring 31 in FIG.5. At this event, the air piston 30 is pushed leftward by compressed airagainst the resistance of the spring-31.

When the air piston 30 reaches a position shown by a hypothetical line,an exhaust outlet 32 in communication with a conduit 33 allowscompressed air to enter a chamber 34 to compress air therein in order topush an exhaust valve 35 leftward in FIG. 5. Hence, the air chamber 29comes in communication with an exhaust chamber 36, and the compressedair flowing into the air chamber 29 enters the exhaust chamber 36directly.

The exhaust chamber 36 is formed to open into the atmosphere through anopening 36', so the air pressure in the air chamber 29 is reduced topush the piston 30 rightward by the force of the spring 31 in FIG. 5. Onpushing the piston 30 rightward, the exhaust outlet 32 is closed by thepiston 30. The outer end of the piston 30 pushes a boss 50 provided onthe left side of the exhaust valve 35 to close it and increase the airpressure in the air chamber 29 again, because compressed air iscontinually supplied thereinto. At this event, the communication betweenexhaust chamber 36 and air chamber 29 is interrupted by the exhaustvalve 35.

Thus, the piston 30 effects a reciprocating motion, and a plunger 37integral with the piston 30' does a reciprocating motion within an oilpump 38 in the form of a cylinder. When the plunger 37 retractsrightward, oil 60 in the oil hydraulic means 3 is absorbed into the oilpump 38 through an oil strainer 42 and a nonreturn valve 43. When theplunger 37 proceeds, the oil in the oil pump 38 is forced into the oilcylinder 47 through the non-return valves 43 and 45 to push a piston 48and a piston rod 49 forwardly (leftward in FIG.

The extreme end of the piston rod 49 is pivotally connected to 49' to aslot 51 at the trailing end of a driving arm 55, the upper end of whichis pivotally supported on a cross beam 52 secured to the frame 1 of thejack, therefore, when the piston rod 49 proceeds forwardly, a load plate53 secured to the forward end of the driving arm 55 rises up.

There is provided a connecting rod 54 which connects the load plate 53and the driving arm 55, hence the load plate 53 is constructed tomaintain its horizontal position at all times.

The oil hydraulic means 3 is connected to the oil cylinder 47 by meansof a connecting member 39, within which the non-return valves 43 and 45are provided. There is provided an arm 44 on either side of theconnecting member 39.

An operating lever for controlling two valves at a remote position, oneof the essential features of the invention, will be describedhereinbelow. The operating lever 22 is provided on a steering hollowshaft 4 of the jack as shown in FIG. 1. The operating lever 22 isadapted to control a needle valve 56 (FIG. 5) in the oil hydraulic means3 and the air valve 27 (FIG. 5) in the air outlet 17, respectively, froma relatively remote position.

As clearly shown in FIGS. 1 and 6, the operating lever 22 is projectedvertically from the upper end of a rod 7 housed in the tubular steeringshaft 4 through a T-shaped slot drilled thereinto. The operating lever22 is adapted to swing left and right along a transverse groove of slot20 at right angle to the axis of the shaft 4, and besides, be pulledupwardly along an axial groove of slot 20.

The lower portion 6 of the rod 7 integral with the operating lever 22 isslidably inserted into a hollow shank of a bifurcated metallic fixture5. Both ends of two arms of the bifurcated fixture 5 are loosely mountedon a shaft 23 (FIGS. 1-4), both ends of which are secured to the frame 1of the jack. As two arms of the fixture 5 are loosely mounted on theshaft 23, the fixture 5 is adapted to swing up and down relative to theshaft 23.

An extreme end 21 of the lower portion 6 of the rod 7 integral with theoperating lever 22 is formed in a crescent shape in section as shown inFIGS. 3-4. This crescent end may be formed by various metal workingsteps, such as, forming it integral with the lower portion 6 of the rod7, and attaching it to the rod by welding, screwing or keying.

As shown in FIGS. 3-4, a pair of similar shape disks 58 and 59 areloosely mounted on the shaft 23 on either side of the rod 6 with thecrescent end 21. A plurality of projections 11a, 11b, 110, 12a, 12b, 12cin FIG. 1 are provided on the circumferences of two disks, respectively.

Three projections 11a, 11b and 11c are attached on the circumference ofthe disk 58, and three projections 12a, 12b and are similarly attachedon the circumference of the disk 59. In addition, three slots 18a, 18band which correspond to the projections, respectively are drilledthrough a mounting plate 61 (FIG. 1) fixed to the frame 1.

As described hereinbefore, the end 6 of the rod 7 is inserted into thehollow shank of the bifurcated fixture 5 so as to slide up and downtherein. Therefore, the end 6 of the rod 7 is adapted to be removed fromthe shank and inserted into one of the slots 18a, 18b and 18c, wherebythe end 6 is positioned at any desired projection of the disks 58 and59. When the crescent end 6 of the rod 7 is engaged with the projections11a and 12a of the disks, the steering shaft 4 is positioned at thehighest level; when engaged with the projections 11b and 12b, the shaft4 is positioned at the intermediate level; and when engaged with theprojections 11c and 120, it is at the lowest level. Depending on theheight of the operator or the level of the working space where theoperator works, there is an advantage from the above means that anylevel of position of the steering handle of the jack can be selected asdesired.

The disk 59 is connected to one end of a connecting rod 14, the otherend of which is connected to the needle valve 56 of the oil hydraulicmeans 3. When the disk 59 moves backward, the needle valve 56 movesbackward against the action of a spring 62 which urges it forward toopen itself. Similarly, the disk 58 is connected to one end of aconnecting rod 13, the other end of which is connected to a pusher 26pivotally connected at 24 to a lever 25, whereby the air valve 27 of theair chamber can be controlled. When the connecting rod 13 is pulledbackward, the air valve 27 is pushed downward by the pusher 26 againstthe action of a spring 63 to open itself.

Now, the operator stands by the steering handle of the jack face to facewith the operating lever 22, and swings it right along the transverseslot 20, the connecting rod 14 is pulled backward to open the needlevalve 56. When he swings the lever 22 left, the connecting rod 13 ispulled backward to make the end of the lever 25 push the pusher 26downward with the result that the air valve 27 connected to the pusher26 is pushed downward to open for the infiow of compressed air. It isbecause when the lever 22 swings leftward the crescent end of the rod 6moves the projection 11a, and when it swings rightward, the crescent end6 moves the projection 12a in the same manner.

In this case, it should be noted that a requirement when assembled isthat the center line of the shaft 6 should intersect the center line ofperpendicular to the diameter of the crescent end. If this requirementis not met, the action of crescent end may be so unstable that bothprojections 11a and 12a may be simultaneously moved, which should becompletely obviated.

It is to be noted that the crescent end of rod 7 should not be alwayspreferred in order to move either of the disks 58 and 59 selectively.For example, a bifurcated end of rod 7 may be preferred.

The needle valve 56 is always closed by the spring 62. On opening theneedle valve 56 by the actuation of the operating lever 22, thecompressed oil in the oil cylinder 47 escapes through the passage 57into the oil hydraulic means 3 to reduce the oil pressure and drop theload plate 53.

In operation, the steering shaft 4 is positioned at a desired level, theair inlet 15 is connected to the source of compressed air, the lever 22is swung left to open the air valve 27 so that the air piston is drivento operate the oil hydraulic motor 3 in order to lift the load plate 53.When the load plate 53 is required to stop at a desired position, theoperating lever 22 for the air valve should be preferred to stand erect.If the load plate 53 is desired to drop, the operating lever 22 shouldbe preferred to swing right.

While the invention has been described with particular reference to theconstruction shown in the drawing, it is to be understood that such isnot to be construed as imparting limitations upon the invention, whichis best defined by the claims appended hereto.

What is claimed is:

1. In an oil hydraulic jack driven by compressed air in which there isprovided an oil cylinder including a piston for lifting a load, an oilpressure generating means driven by a reciprocating plunger which isdriven by compressed air, and said oil pressure is delivered into saidoil cylinder, the improvement which comprises:

(a) a rod rotatably axially housed in a hollow tubular steering shaft,

(b) a valve for supplying compressed air which drives said oil hydraulicmeans,

(c) a valve for escaping hydraulic oil in said oil cylinder, and

((1) means operatively connected to said rod for selectively controllingsaid two valves of (b) and (c) by rotating said rod in said steeringshaft.

2. In a pneumatic and oil hydraulic jack for garage use comprising ajack body, an oil pressure cylinder for lifting a load, a hollow tubularsteering shaft connected to said jack body, a rod housed in a hollowspace of said steering shaft, an operating lever secured to said rod, an

engaging member formed at the lower end of said rod, an air piston fordriving an oil piston for increasing oil pressure, a valve for supplyingcompressed air to drive said air piston, an exhaust valve for exhaustinghydraulic oil in said oil cylinder, a pair of disks engageable with saidengaging member, a control rod connected to said disk to control saidvalve for supplying compressed air, and a control rod connected to saiddisk to control said valve for escaping hydraulic oil.

3. A pneumatic and hydraulic jack as defined in claim 2 in which saidoperating lever is secured to said rod through a T-shaped slot drilledin said tubular steering shaft.

4. A pneumatic and hydraulic jack as defined in claim 2 in which saidoperating lever is adapted to swing left and right along a transversegroove of said slot, and control one valve when swung left and the othervalve when swung right.

5. A pneumatic and hydraulic jack as defined in claim 2 in which saidpair of disks are provided with a plurality of projections on thecircumferences thereof, respectively, and adapted to position saidsteering shaft at a desired position when engaged with said engagingmember of said rod.

6. A pneumatic and hydraulic jack as defined in claim 2 in which saidengaging member formed at the lower end of said rod is a bifurcatedmember.

7. A pneumatic and hydraulic jack as defined in claim 2 in which saidengaging member formed at the lower end of said rod is a crescentmember.

References Cited UNITED STATES PATENTS 2,213,285 9/1940 Nilson 254-93 X2,974,490 3/1961 Hott 25493 X LESTER M. SWINGLE, Primary Examiner.

D. R. MELTON, Assistant Examiner.

